The present invention relates generally to electrical connectors and, in particular, to an electrical connector for establishing an electrical tap connection to the inner conductor of an unbroken coaxial cable.
Coaxial cable is commonly used to interconnect a variety of electronic devices largely because of its low loss and high shielding characteristics. For example, many computer systems are frequently interconnected by unbroken lengths of such cables. It often becomes necessary, however, to tap an unbroken length of coaxial cable connected between two electronic devices in order to enable the operation of an additional device in response to the signals transmitted over the cable. Thus, one or more additional terminals or computers may be added to a computer system in this manner.
In the past, unbroken lengths of coaxial cable have been tapped by cutting the cable and installing a tee connector between the cut ends, the central leg of the connector being adapted for mating with a branch cable whose other end is connectable to, in the case of the foregoing example, an additional computer terminal. This operation is relatively time consuming requiring the use of at least semi-skilled personnel and assembly tools. In addition, while the cable is cut and for the period of time that it takes to install the tee connector, the complete computer system may be taken out of service. Also, if at some later time it is desired to remove the installed tee connector, the cut cable must either be spliced together which frequently degrades the signal transmission characteristics of the cable or, alternatively, a new cable must be provided.
U.S. Pat. No. 2,805,399 to Leeper discloses a tee type connector which can be used for tapping a coaxial cable but does not require the cable to be cut during the installation procedure. In a preliminary step to the installation of the connector taught in this patent, a continuous radial opening or channel is formed between the central conductor and exterior surface of a coaxial cable. The connector is then installed by guiding a spring loaded conductor stem into the channel for making electrical connection with the cable central conductor while connection is made with the conductive braid surrounding the central conductor by rotating a tapered screw which penetrates the cable and presses firmly against the conductive braid.
Factors such as thermal variations and other stresses imposed on the coaxial cable comprise a major consideration effecting the design of connectors of the type described above. For example, thermal variations in a cable may cause movement of the contact portions of the connector relative to the cable conductors thereby breaking a previously established electrical connection. In order to minimize the possibility of this occurring, the connector design preferably includes apparatus inhibiting any motion between the contact portions of the connector and the cable conductors, which motion could degrade the electrical connection established therebetween.
It is a basic object of the present invention to provide an improved connector assembly for tapping a coaxial cable, which connector assembly may be easily installed without any installation tools or the like and without requiring the performance of any preliminary cable conditioning steps.
It is a further object of the invention to provide a connector assembly of the foregoing type wherein an extremely secure connection is effected with the cable conductors, both mechanically and electrically, and wherein the connector assembly may be removed from the cable without degrading the cable's signal transmission characteristics.